Fluids in hydrocarbon formations may be accessed via wellbores that extend down into the ground toward the targeted formations. In some cases, the hydrocarbon formations may have a lower viscosity such that crude oil flows from the formation, through production tubing, and toward the production equipment at the ground surface. Some hydrocarbon formations comprise fluids having a higher viscosity, which may not freely flow from the formation and through the production tubing. These high viscosity fluids in the hydrocarbon formations are occasionally referred to as “heavy oil deposits.” In the past, the high viscosity fluids in the hydrocarbon formations remained untapped due to the inability and expense of recovering them. More recently, as the demand for crude oil has increased, the commercial operations have expanded to the recovery of such heavy oil deposits.
In some circumstances, the application of heated fluids (e.g., steam) to the hydrocarbon formation may reduce the viscosity of the fluids in the formation so as to permit the extraction of crude oil and other liquids from the formation. The design of systems to deliver the steam to the hydrocarbon formations may be affected by a number of factors.
One such factor is the location of the steam generators. If the steam generator is located above the ground surface, steam boilers may be used to create the steam while a long tube extends therefrom to deliver the steam down the wellbore to the targeted formation. Because a substantial portion of the heat energy from the steam may be dissipated as the steam is transported down the wellbore, the requisite energy to generate the steam may be costly and the overall system can be inefficient. If, in the alternative, the steam generators are located downhole (e.g., in the wellbore below the ground surface), the heat energy from the steam may be more efficiently transferred to the hydrocarbon formation, but the amount of heat and steam generated by the downhole device may be limited by the size and orientation of the downhole steam generator and by constraints on the supply of water and fuels. Furthermore, installation of the downhole steam generators, including the attachment of supply tubes that provide water, air, fuel, or the like from the ground surface, may be complex and time consuming.